Photopolymerization-Induced Phase Separation Process of Thin Composite Films of Liquid Crystal and Polymer Fiber Networks

It was clarified that a thin composite film of a liquid crystal (LC) and polymer fiber networks can be obtained through two phase separation processes: spinodal decomposition, and nucleation and growth. The phase separation phenomenon was observed using a polarizing microscope under ultraviolet irradiation. Results showed that spinodal decomposition initially occurred in the LC/polymer solution under photopolymerization of a monomer. The polymer fibers were then grown on a surface of solid materials (such as substrates and spacer particles) by the nucleation and growth process in the polymer-rich solution induced by the spinodal decomposition. It was found that the spatially noncyclic morphology of the polymer fibers dispersed in the LC was obtained by the intervention of the nucleation and growth process after the spinodal decomposition process.